There is a large artery on each side of the neck conveying blood to the head: of so great magnitude is it, that, could the murderer wound it by a puncture only, his business would be sufficiently done, without any further division. A very small wound of this vessel would give vent to so many pounds of blood, in a few seconds, as would cause immediate death. Now this artery is subject to a disease called Aneurism, wherein its coats yield (perhaps on one side of the vessel) so as to form a small pulsating tumour. It is a membranous sac containing blood. It communicates with the interior of the artery, so that the contents of the tumour are easily squeezed back into the artery, whence, upon the removal of the pressure, the blood immediately returns into the sac. This tumour, gradually enlarged by the continuance of morbid actions, and by the impetus of the circulating blood, acquires, perhaps, the size of a large orange. The skin is in a constant state of increasing tension, and it finally becomes inflamed, and ulcerates, and the tumour bursts. After what was said of the size of the artery, I need not dwell upon the certainty of immediate death. The remedy consists in exposing the vessel between the diseased portion and the heart, (_i. e._ in the neck,) and closing it by applying a ligature upon it. This operation well performed, and under favourable circumstances, effects a perfect cure. But it is dreadful for any man to attempt it, (and there are many operations much more difficult,) without the most exact anatomical knowledge. It were far better that he allowed his patient to die _secundum naturam_, than that he presumed to hasten his death, by destroying him _secundum artem_. And, better were it many times over, that he experimented upon his own, than upon the throats of his unfortunate patients. Does he know the exact situation of the artery relatively to the deep parts about it? Does he know by what parts it is covered? Then let him proceed to expose it. It is surrounded by parts vitally important. It is in close contact with a great vein which partially overlaps it, and which is in continual motion. Should he wound this vein ever so slightly, the probability is that the operation is fatal; and yet, he has to separate it from the artery, and this at the bottom of a wound which is covered with blood. Important nerves environ the artery, and to include one of them in the ligature with it, would be as certainly fatal as to injure the vein. Suppose a dexterous man and an anatomist to be the operator: he leaves these important parts uninjured, because he knows their situation, and that of all the parts concerned; also, because he is calm and collected, from a consciousness of his own resources. He exposes a portion of the artery, he conveys a ligature around it, and his patient is safe. Suppose, again, that the operator, from a delicate sentimentality, has held disinterment to outweigh, in